Along with the depth charts and spreadsheets that he has at his fingertips, Cardinals general manager John Mozeliak keeps a ledger that he cracks open in case of injury.
In it is a list of the major-league players and beside each name is the name of the planned replacement should the team need one. If any of the Cardinals go on the disabled list, Mozeliak has the name of a corresponding minor-leaguer already attached. It’s his understudy list. And it’s been utilized often already this season.

The understudies have helped carry the show.

“We want to deal with our problems internally,” Mozeliak said. “It’s not always going to work out, but when you lose a Chris Carpenter and a Rafael Furcal and a Jason Motte all within an eight-week period we didn’t feel like we had to panic to still be successful to still put a good product on the field. The reason was because we have depth in our minor leagues and we’re not afraid to give that depth an opportunity.”

Through two months, those opportunities have been necessities — and not just for filling holes in the roster. The Cardinals, a mid-market team with a top-third payroll, have been able to maintain both a budget and performance even with almost a third of its $115-million payroll inactive. The Cardinals entered the weekend with four players on the disabled list, a group led by veteran ace Carpenter and making a combined $32.3 million in salary this season. A fifth, Jaime Garcia, will go on the DL on Sunday. On Saturday, the Cardinals had two other players, relievers Marc Rzepczynski and Mitchell Boggs, drawing major-league salaries at Class AAA Memphis. Boggs returns to the majors Sunday and Garcia’s move to the DL brings the total of salaries not contributing to the big-league club to $39.1 million, or approximately 34 percent of the total payroll.

With Garcia on the DL, the Cardinals have the third-most payroll on the disabled list in the majors, according to numbers for the other major-league teams calculated by The New York Times. Add in Rzepczynski and the Cardinals’ percentage of payroll that’s inactive in the majors is the third-highest behind only the Yankees and Mets.

“It’s not all about payroll,” Cardinals chairman Bill DeWitt Jr. told the Post-Dispatch during spring training. “It’s about getting value for the dollars you do spend. There is clearly an advantage to being in the top third in payroll. We still need to spend the money wisely because there are those who can outspend us.”

Enter the Yankees.

With lefty Andy Pettitte going on the 15-day disabled list Friday afternoon, the Yankees have nearly a half of their enormous payroll on the DL. Pettitte’s $12-million salary joins Alex Rodriguez’s $29-million salary and Derek Jeter’s $17-million salary on an inactive squad that looks like an All-Star roster. The Yankees’ DL total of $97.6 million would be the 14th highest in baseball — on its own.

And yet the Yankees, like the Cardinals, lead their division despite the litany of injuries. How each has overcome the absences says as much about their payrolls, market and approach as any free-agent hunt, and it speaks to how the Cardinals intend to contend in a sport with skyrocketing payrolls fueled by broadcast rights.

In a series of moves at the start of the regular season, the Yankees papered over the holes in their roster with veterans. They acquired or signed Lyle Overbay (age 35), Travis Hafner (35), and Vernon Wells (34) to go with replacement addition Kevin Youkilis (34), who signed in the winter shortly after Rodriguez’s hip injury was revealed. The Yankees will pay Youkilis, Hafner and Wells a combined $25.5 million this season. The Yankees, who plan to cut payroll at the end of the season, still threw money at the injuries.